Study On The Effect Of Freezing And Storage Of Freezing Point Temperature On The Quality Of Tangyuan

Tangyuan is one of the traditional snacks widely enjoyed by the people of our country.At present,quick-frozen Tangyuan produce a lot of energy during the production and storage process,and they emit large amounts of greenhouse gases to pollute the environment.Research and development of frozen-point temperature Tangyuan is of great significance for reducing energy consumption and protecting the environment.In this paper,more than twenty varieties of glutinous rice flour were used to measure the freezing point temperature,basic composition and physicochemical indexes,and the main factors affecting the freezing point temperature were analyzed.On this basis,the glutinous rice flour dough was frozen at the freezing point,and compared with the traditional quick-frozen glutinous rice flour dough for cooking quality characteristics and water migration.The glutinous rice flour was used as a raw material to make Tangyuan,and the Tangyuan were stored at freezing point temperature and-18°C for 210 days respectively,during the period,the acid price,the peroxide value,the texture characteristics and the quality characteristics of the cooking quality were measured and compared.The difference of energy consumption in the storage conditions of the two kinds of Tangyuan was measured,and the energy saving rate was calculated and the storage cost was analyzed.The main conclusions are as follows:(1)The starch content of different varieties of glutinous rice flour had little difference and the ash content varied greatly.The physical and chemical indexes of different glutinous rice flour varieties are quite different.The differences among the peak temperature,initial temperature,and end temperature index of different glutinous rice flour varieties are smaller.The freezing point temperature of more than twenty glutinous rice flour was measured between-2.5 and-1.5.The correlation analysis and principal component analysis were carried out on the temperature of the freezing point and the basic composition,physicochemical and thermal properties of glutinous rice powder.The key factors for the freezing point temperature of glutinous rice flour are the crude fat content,solubility,the average particle size of glutinous rice flour,and the peak temperature,initial temperature,and termination temperature of glutinous rice flour.(2)The L* value and light transmittance of the glutinous rice dough frozen at freezing point temperature for 10min~25min were higher.The hardness,chewiness and adhesion of the glutinous rice dough frozen at freezing point temperature were better,and the water holding property of the glutinous rice dough frozen at freezing point temperature was better.Combined sensory evaluation score results show that the glutinous rice dough frozen at freezing point for 15 min ~ 25 min were better.(3)The acid value and peroxide value of the two kinds of Tangyuan gradually increased over time and did not exceed the national standard.The Tangyuan cracking rate of frozen storage in freezing point during storage was slightly higher than that of frozen storage at-18℃,but it was still in normal range.The L* value and transmittance of frozen at freezing point Tangyuan during storage are better than that of frozen Tangyuan at-18℃.The total score of sensory evaluation of freezing point Tangyuan was higher than that of-18℃ at 150 days ago.A shelf life prediction model based on acid and peroxide values was established and verified.The energy consumption of the two storage methods was measured.The energy-saving rate of the Tangyuan frozen at the freezing point is much greater than that of the frozen Tangyuan at-18°C,which can save the cost of frozen storage,and significantly reduce energy consumption and greenhouse gas emissions.